This invention relates to a novel active material for the negative electrode that contains a heretofore unavailable metallic element or alloys thereof as a principal component. More specifically, the invention relates to novel primary or secondary battery that is characterized by using as the negative electrode a current collector that is filled or impregnated with an active material that contains metallic gallium or gallium alloys as a principal component.
The use of various active materials, either independently or in combination, for the negative electrode in primary or secondary batteries has been the subject of intensive studies; however, what have been commercialized are limited to lead in lead-acid storage batteries, cadmium in nickel-cadmium rechargeable cells, hydrogen containing alloys in hydrogen batteries, zinc in alkaline cells, lithium in lithium cells and few others.
Because of this limitation on the types of active materials for the negative electrode which determine the basic cell performance, only a few kinds of primary or secondary batteries have been commercialized and their defects cannot be fully cancelled by using them in combination. Under the circumstances, the following problems have arisen.
(1) Dendrites form on the surfaces of electrodes as a result of charge-discharge cycles; PA0 (2) the active materials per se or the materials that precipitate during charge and discharge cycles have such low electric conductivity that large currents are difficult to produce; PA0 (3) the voltage that can be produced is impractically low; PA0 (4) the high chemical activity causes difficulty in handling; and PA0 (5) the toxicity problem.